tl;dr = There are little spearheads all over the island. An expert in spear-heads looked at them and said they aren't very practical as spearheads, and thy are

tl;dr = There are little spearheads all over the island. An expert in spear-heads looked at them and said they aren't very practical as spearheads, and thy are probably not weapons at all. The authors attribute deforestation to the arrival of rats, not to weird cult rituals.